<!DOCTYPE html>
<select id="test-select">
    <option value="0" selected>Option 0</option>
    <optgroup label="Group 1">
        <option value="1">Option 1</option>
        <option value="2">Option 2</option>
    </optgroup>
    <option value="3" selected>Option 3</option>
    <option value="4">Option 4</option>
</select>
<script src="../include.js"></script>
<script>
    test(() => {
        const selectElement = document.getElementById('test-select');
        println(selectElement.selectedIndex);
    });
</script>
